Rep Power: 0

My car is a 2001 Honda Civic (MK7), with an Automatic gearbox, and I am in the UK.
The car doesn't start, and makes no sound, when trying to start it.
The green key light keeps flashing and doesn't go out, which I understand means the key is not being recognized.
I have tried the spare key for the car, and that doesn't work either.
A Honda dealer garage have tested the car with diagnosis equipment, and say the Multiplex within the Cabin fuse box is faulty, and the Cabin fuse box would need to be replaced. The part is no longer made, so I can't get a new Cabin fuse box.
Does it sound like the fault would be in the Multiplex within the cabin fuse box? Can they be repaired, as I can't get a new replacement?

 
Rep Power: 223

You would have to find one in a junkyard. It will have to come out of a car with the same engine, trans, and in your case from an 01-02. Once installed the dealer will have to program it.

 
Rep Power: 0

The central locking of the car doesn't work either, as well as the green key light which keeps flashing when trying to start it.
Are these issues connected, in some way?

 
Rep Power: 223

It shouldn't affect it